a. It's understandable, especially if you're a bit shy in a new situation. But it's probably better to just open up and risk putting your foot in it. You'll be amazed how responsive people can be, once they realise you're genuinely interested.

b. Why on earth not? People are people - it's just that ours come from all over the world. You need to be comfortable around people from different continents and cultures - otherwise you'll never get on with our guests!